1. Field of the Invention
The invention relates to a stretch of gene promoter capable of activating expression specifically in plant tissue, and in particular, to a promoter capable of activating expression specifically in calyx, petal and stamen of a plant floral organ, as well as to the application of said promoter.
2. Description of the Prior Art
In transgenic plants, the target gene to be transferred into the plant has to be constructed downstream of a promoter usable by the plant. After transformation, the expression of said target gene in the transgenic plant can be activated by the action of said promoter. The CaMV 35S promoter is the most commonly used promoter for driving target gene expression in plants. However, CaMV 35S promoter does not exhibit tissue specificity, and hence can not carry out the expression of the target gene in a specific plant tissue to achieve the purpose of modulating a gene expression. Further, it exhibits lower activity in monocot plants, such as orchid, than in dicot plants.
In some cases, constitutive over-expression of a transgenic target gene may interfere with the normal physiological processes in a plant. The development of tissue-specific promoters to drive a particular gene of interest should help to alleviate these problems. Therefore, the isolation and development of floral specific promoters from monocots is necessary. To modulate the expression of a target gene in transgenic plants, the critical point for modulating a gene expression is how to make a strong expression of a target gene at a specific tissue organ and/or a specific phase other than carrying out a strong expression of a target gene in the transgenic plant. Therefore, one of the important topics in promoting industrial development is to screen each promoter with different a specificity that can be used as various tools for modulating gene expression so that the transferred promoter can support the production of recombinant protein, as well as a promoter having activating ability with space specificity so as to attain the function of modulating gene expression and hence increase economical benefit.
In view of the foregoing, it is evident that CaMV 35S promoter has many disadvantages, is not designed perfectly and needs to be urgently improved.
The inventor had recognized various disadvantages derived from the conventional CaMV 35S promoter described above, and had devoted to improve and innovate. After studying intensively for many years, the inventor has developed a promoter capable of activating expression specifically in a floral organ tissue according to the invention and the application thereof.